UK government outed IRA double agent. Senior Irish Provisional Army volunteer Denis Donaldson, who spied for the British government, was deliberately outed by the government to send a message to the IRA that he was expendable, and that it had another, more valuable informant within the IRA leadership ranks. The revelation is contained in a leaked US diplomatic document published by whistleblower website WikiLeaks. Donaldson was shot dead shortly after his role as an MI5 informant was revealed.